Xorg: xwayland: buffer overflow in xkbvmodmasktext()

Summary

A buffer overflow flaw was found in X.Org and Xwayland. The code in XkbVModMaskText() allocates a fixed-sized buffer on the stack and copies the names of the virtual modifiers to that buffer. The code fails to check the bounds of the buffer and would copy the data regardless of the size.

Timeline

1. Feb 25, 2025, 3:54 PM UTCCVE published
2. Feb 25, 2025, 8:05 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: total

3. Jun 29, 2026, 8:36 PM UTCRecord last updated

Affected versions

• xserver

  fixed in 21.1.16; From 22.0.0 · fixed in 24.1.6

• xorg-x11-server-Xwayland

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• xorg-x11-server

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• xorg-x11-server

  Version range not reported

• xorg-x11-server-Xwayland

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• tigervnc

  Version range not reported

• xorg-x11-server

  Version range not reported

• xorg-x11-server

  Version range not reported

• xorg-x11-server-Xwayland

  Version range not reported

References 17